USO0RE42747E
(19) United States (12) Reissued Patent
(10) Patent Number: US (45) Date of Reissued Patent:
Hong et a]. (54)
(56)
FILTERING CONTROL METHOD FOR IMPROVING IMAGE QUALITY OF
4,550,437 5,208,872 5,274,469 5,696,848 5,821,915
Yoon-Seong Soh, Seoul (KR)
(73) Assignee: LG Electronics Inc., Seoul (KR) (*)
Notice:
This patent is subject to a terminal dis claimer.
(22) Filed:
U.S. PATENT DOCUMENTS A 10/1985 Kobayashi et a1. A A A A
Apr. 16, 2009
5/1993 12/1993 12/1997 10/1998
Fisher Small et al. Patti Graham et a1.
5,875,268 A
2/1999 Miyake
5,880,767 A
3/1999 Liu
5,917,963 A
6/1999 Miyake
5,949,914 A 5,991,464 A 6,058,248 A
(21) Appl. No.: 12/424,927
Sep. 27, 2011
References Cited
BI-LINEAR INTERPOLATED IMAGE
(75) Inventors: Min-Cheol Hong, Seoul (KR);
RE42,747 E
9/1999 Yuen 11/1999 Hsu 5/2000 Atkins et al.
6,072,907 A
6/2000 Taylor
6,075,926 A 6,236,433 B1
6/2000 Atkins 5/2001 Acharya et al.
(Continued)
Related US. Patent Documents OTHER PUBLICATIONS
Reissue of:
(64)
Patent No.:
6,803,954
Of?ce Action for US. Appl. No. 12/024,408, mailed Jun. 29, 2009, 7
Issued:
061. 12, 2004
pages.
Appl. No.:
09/692,156
Filed:
061. 20, 2000
(Continued)
U.S. Applications:
Primary Examiner * Brian Le
(63)
Continuation of application No. 11/546,484, ?led on Oct. 12, 2006, noW Pat. No. Re. 42,045.
(74) Attorney, Agent, or Firm * Fish & Richardson PC.
(30)
Foreign Application Priority Data
Oct. 21, 1999
(51)
(KR) ............................... .. 1999/45805
Int. Cl.
compressed image system as a sub-pixel unit When the image digitized through a CCD (Charge Coupled Device) camera
or general digital video system, particularly the present inven
(2006.01)
US. Cl. ...... .. 382/260; 382/261; 382/262; 382/263;
382/264
(58)
ABSTRACT
ect. has a loW resolution in a video phone or video conference
G06K 9/40
(52)
(57)
The present invention relates to an interpolation method for enlarging a digital image or predicting a moving vector of a
Field of Classi?cation Search ................ .. 382/260,
382/261, 262, 263, 264, 298, 299, 300; 358/525;
tion can be adapted to a post processor of a compressed digital
image in order to improve the image quality, and can be used for ?nding a moving vector of a moving picture compressed
type, accordingly the present invention is capable of improv
ing the image quality.
345/33, 698 See application ?le for complete search history.
—A-
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67 195 232 13 76 156 —16 0 15 35 55
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M 4/512 N 0 P Q R s T u v w
11 Claims, 4 Drawing Sheets
- —1
—9 —2 -3 -4 —9
—11 0 —16 0 —14 -2 —13 -4 —14 —5
n o —Pa
US RE42,747 E Page 2 US. PATENT DOCUMENTS 6,263,120 B1 6,285,804 B1 6,331,902 B1 6,442,202 B1 *
6,912,004 B1
7/2001 Matsuoka 9/2001 Crinon 12/2001 Lin 8/2002
Borer
..................... ..
6,567,568 B1
5/2003 Nabeshima
6,577,320 B1 *
6/2003
6/2005 Knudsen et a1.
OTHER PUBLICATIONS Of?ce Action for U.S.Appl. No. 12/024,408, mailed Dec. 4, 2008, 10 375/240.16
Kirk ............................ .. 345/582
pages.
* cited by examiner
US. Patent
Sep. 27, 2011
Sheet 1 M4
US RE42,747 E
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US. Patent
Sep.27,2011
Sheet 2 of4
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Sep. 27, 2011
Sheet 3 M4
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US RE42,747 E
US RE42,747 E 1
2
FILTERING CONTROL METHOD FOR
tioned method such as the bi-linear interpolation method,
IMPROVING IMAGE QUALITY OF BI-LINEAR INTERPOLATED IMAGE
zero order hold expansion method, cubic spline method, the outlines of the image is over-blurred. Meanwhile, the image enhancement type method com
Matter enclosed in heavy brackets [ ] appears in the original patent but forms no part of this reissue speci?ca
method causes a computational complexity, accordingly the
prises many methods, but the image enhancement type method is not suited to a real-time processing due to the its
tion; matter printed in italics indicates the additions made by reissue.
computational complexity.
20
In addition, when the image enhancement type method is used for getting the high resolution image from the low reso lution image, setting of each parameter is not adaptable. For example, there is a POCS (Projection Onto Convex Set) method for increasing the resolution of an image. In the POCS method, in use of time region information, it is assumed as correlation between the images is uniformly same, but actually the correlation between the images is not uniform. In addition, there is a mapping method for mapping a non-uniform sample of the low resolution image into a uni
25
information and segmentation information of the image. However, the mapping method has the computational com plexity problem, accordingly the mapping method is not suited to the real-time image data processing of the image
CROSS-REFERENCE T0 RELATED APPLICATIONS
NOTICE: More than one reissue application has been?led
for the reissue ofU.S. Pat. No. 6,803,954, including reissue application Ser No. 12/424, 92 7; US. patent application Ser. No. 12/024,408, which is a divisional reissue ofU.S. Pat. No.
6,803,954; and US. patent application Ser No. 11/546,484, which is a reissue of US. Pat. No. 6,803,954. Accordingly, this application is a continuation application of US. patent application Ser. No. 11/546, 484,?led Oct. 12, 2006, now US. Pat. No. Re. 42, 045, which is a reissue ofU.S. application Ser. No. 09/692,156,?led Oct. 20, 2000, now US. Pat. No. 6,803,
form sample of the high resolution image by using moving
954, which claims the bene?t ofaforeignpriority application filed in Korea as SerialNo. 1999/45805 on Oct. 21, 1999. The
disclosures of the prior applications are considered part of (and are incorporated by reference in) the disclosure of this
processing system.
application. BACKGROUND OF THE INVENTION
SUMMARY OF THE INVENTION 30
1. Field of the Invention The present invention relates to an interpolation method adapted to enlargement of a low resolution image when the
image digitized through a CCD (Charged-Coupled Device)
interpolated image which is capable of improving the image quality of the interpolated image by using an interpolation 35
has the low resolution, in particular to a ?ltering control method for improving the image quality of a bi-linear inter
polated image which is capable of restoring a requested inter polated high resolution image from a low resolution image by ?nding a coef?cient of a two-dimensional ?lter on the basis of
40
a regularization image restoration method. 2. Description of the Prior Art In the conventional technology, a still picture or a moving picture has or transmits a low resolution image because it can not physically satisfy a sensor having the low resolution or a
45
frequency region. 50
The other object of the present invention is to provide the
?ltering control method for improving the image quality of the bi-linear interpolated image which is capable of perform ing a real-time adaptive processing by ?nding a ?lter coef? cient from the bi-linear interpolated image and approximated
enlarges the transmitted moving picture, the resolution of the transmitted moving picture lowers due to a degradation phe nomenon ect. 55
60
the low resolution image into a requested size. The bi-linear interpolation method, a zero order expansion method, and a
cubic spline method are comprised in the image expansion type method. However, as described above, the image expansion type method has an image visibility lowering problem because when the image is interpolation-restored by the above-men
?ltering control method for improving the image quality of the bi-linear interpolated image which can approximate and ?nd a PSF (Point Spread Function) for the bi-linear interpo lated image from a modeling of the degraded image in the
For example, when the compressed moving picture having
image expansion type method and an image enhancement type method. First, the image expansion type method converts the size of
seeks the interpolated image from the low resolution image. The other object of the present invention is to provide the ?ltering control method for improving the image quality of the bi-linear interpolated image which is capable of ?nding a two-dimensional ?lter coef?cient for getting the interpolated larization image restoration method. The other object of the present invention is to provide the
In addition, a compressed moving picture has or transmits the low resolution image due to its bit value problem.
Accordingly, a method for getting a high resolution image from a low resolution image is required. In the meantime, the method for getting the high resolution image from the low resolution image is largely divided into an
method considering a real-time processing, a computational complexity and an ef?ciency when the digital video system
image from the low resolution image on the basis of a regu
nyquist value.
the low bit value is transmitted to a receiver and the receiver
The object of the present invention is to provide a ?ltering control method for improving the image quality of a bi-linear
PSF. In the present invention, in order to ?nd a ?lter coef?cient
for ?nding the interpolated image from the low resolution image on the basis of the regularization image restoration method, when H is the PSF (Point Spread Function), f is a requested high resolution image, Z is the low resolution image, g is the high resolution image gotten from the bi-linear interpolation method, an added function M (f):||g—Hf]|2+
(XIICf H2 for ?nding the PSF(H) from an equation g:Bz:Hf+n (B, H are bi-linear interpolated ?lters, n is a noise component 65
generated by the assumed H) is de?ned. The ?ltering control method for improving the image qual ity of the bi-linear interpolated image can be implemented by
US RE42,747 E 4
3 ?nding the PSF(H) from the added function M(f) by using an
As depicted in FIG. 3, a~p illustrate the loW resolution
equation
pixels, A~I illustrate the high resolution pixels using the ?lter according to the present invention. FIG. 4 illustrates the interpolation ?lter coef?cient for get ting the three times enlarged image according to the other embodiment of the present invention. As depicted in FIG. 4, three times enlarged pixels Which
G(k, 1) H(k, 1) = m.
The ?ltering control method for improving the image qual ity of the bi-linear interpolated image can be implemented by ?nding a PSF(P) of a fIPg function by using an equation
are neWly generated illustrated as triangles in FIG. 3 are
gotten from the loW resolution pixels a~p (4x4 pixels) by using the interpolation ?lter coe?icient of FIG. 4. FIG. 5 illustrates the image sample for getting a six times
enlarged high resolution image according to the another embodiment of the present invention. In other Words, it illus
trates the image sample for getting the six times enlarged high resolution image from the tWice and three times interpolation ?lter coef?cients by using the bi-linear interpolation method.
The ?ltering control method for improving the image qual ity of the bi-linear interpolated image can restore the
requested high resolution image(f) by ?nding an added ?lter coe?icient Q of the PSF(P) and interpolation ?lter B from the
20
equation fIPgIPBZIQZ. BRIEF DESCRIPTION OF THE DRAWINGS 25
lation method.
enlarged high resolution image according to the embodiment ting the tWice enlarged image according to the embodiment of the present invention. FIG. 3 illustrates an image sample for getting a three times
FIG. 6 illustrates the interpolation ?lter coef?cient for get 30
ting the six times enlarged image according to the another embodiment of the present invention. In other Words, the
interpolation ?lter coef?cient for getting the six times enlarged image of FIG. 5 is depicted in FIG. 6.
enlarged high resolution image according to the other embodiment of the present invention. FIG. 4 illustrates the interpolation ?lter coe?icient for get
pixels illustrated as a triangle can be gotten by using the three times interpolation ?lter coe?icient of FIG. 4. In addition, pixels illustrated as a quadrilateral can be got ten from the pixels generated by the tWice and three times
interpolation ?lter coef?cients by using the bi-linear interpo
FIG. 1 illustrates an image sample for getting a tWice
of the present invention. FIG. 2 illustrates an interpolation ?lter coe?icient for get
As depicted in FIG. 5, pixels illustrated as a ‘X’ can be
gotten by using the tWice interpolation ?lter of FIG. 2, and
Meanwhile, as depicted in FIG. 2, FIG. 4 and FIG. 6, the 35
value found by using the interpolation ?lter coe?icient of the present invention has an integer value. In addition, a 9 bit shift is performed to the value calculated
ting the three times enlarged image according to the other embodiment of the present invention. FIG. 5 illustrates an image sample for getting a six times embodiment of the present invention. FIG. 6 illustrates the interpolation ?lter coe?icient for get
by the interpolation ?lter coef?cient, accordingly there is no need to perform a ?oating point operation processing. The tWice, three times, six times interpolated images are depicted in FIG. 1~FIG. 6, hoWever the present invention is
ting the six times enlarged image according to the another
not limited by that, it can be adapted freely to a certain
enlarged high resolution image according to the another
40
embodiment of the present invention. 45
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
described in more detail.
FIG. 1 illustrates an image sample for getting a tWice
enlarged high resolution image according to the embodiment
50
of the present invention. As depicted in FIG. 1, a~i illustrate loW resolution pixels,
A~D illustrate high resolution pixels. In addition, pixels depicted as ‘x’ illustrate pixels interpolated as tWice by a
tWice interpolation ?lter coe?icient. FIG. 2 illustrates the interpolation ?lter coe?icient for get ting a tWice enlarged image according to the embodiment of the present invention. In other Words, the interpolation ?lter coe?icient for interpolating the tWice enlarged image of FIG. 1 is depicted in FIG. 2. As depicted in FIG. 2, the high resolution image is gotten from the loW resolution pixels a~i (3x3 pixels) inside of a circle of FIG. 1 by using the interpolation ?lter coe?icient. FIG. 3 illustrates an image sample for getting a three times
interpolation value. Hereinafter, the ?ltering control method for improving the image quality of the bi-linear interpolated image Will be
55
First, a spatially invariant PSF (Point Spread Function) for ?nding the interpolation ?lter coe?icient according to the each interpolation value can be easily analyZed and approxi
mated in the frequency region, accordingly the spatially invariant PSF (Point Spread Function) is considered from the bi-linear interpolated image. After that, When it is assumed as the loW resolution image
is Z, high resolution image gotten by the bi-linear interpola tion method is g, high resolution image to be restored is f, the relation betWeen the each image can be described as beloW. 60
Herein, the B, H, n are the bi-linear interpolation ?lters, H is the spatially invariant PSF de?ning the relation betWeen the 65
original high resolution image and high resolution image
enlarged high resolution image according to the other
gotten by the interpolation method, and the n is a noise com
embodiment of the present invention.
ponent generated by the assumed H.
US RE42,747 E 5
6
Herein, when the noise component is neglected and a direct inverse is used in order to ?nd the PSF(H), the PSF(H) can be described as below equation 2 in the frequency region.
tion 5 is a block-circulant matrix, accordingly it can be easily
calculated in the frequency region. Accordingly, the PSF(P) can be found ?nally as below
Equation 6. Hui, 1) :
[Equation 2] Pug 1) :
Herein, the H(k,l) is the component in the k,l frequency region of the PSF(H), the G (k,l) is the component in the k,l frequency region of the bi-linear interpolated image. In addi tion, the F (k,l) is the component in the k,l frequency region of
[Equation 6]
Herein, the ‘*’ the means a complex-conjugate.
The PSF(P) can be found by using an IFT (Inverse Fourier
Transform) from Equation 6.
the high resolution image.
The requested high resolution image f can be found as
below Equation 7 by using the found PSF(P) and Equation 1.
Meanwhile, the high resolution image f to be restored is unknown, the PSF(H) can be gotten from the bi-linear inter
fIPgIPBZIQZ
polated high resolution image through a statistical processing after performing an under-sample processing of various
[Equation 7]
The PSF(P) is the spatially invariant function, the bi-linear interpolation ?lter B can be easily found by the conventional technology, accordingly the added ?lter coe?icient Q of the
images as various value.
Herein, the high resolution image is gotten by using the PSF(H) found from the direct inverse. In other words, there is a system stabilization problem because the high resolution
PSF(P) and bi-linear interpolation ?lter B can be found.
Herein, in order to reduce the computational complexity,
image gotten from the PSF(H) by using the direct inverse is
the number of a kernel of the PSF(P) is set in accordance with
overshoot in the region where the k,l have ‘0’ value (in gen
the up-sampling value. When the up-sampling value is 2 in the present invention,
eral, high frequency region) in the frequency region, accord ingly the regularization image restoration for improving the
the number of the kernel is limited as 3, when the up-sampling value is 3, the number of the kernel is limited as 4. When the up-sampling value is 2, it can be used in an
system stabilization is used to solve the problem. The regularization image restoration method is used for restoring the image or ?nding a certain PSF, an added func
application segment for enlarging the size of the image as twice at a post processor of the compressed digital image and in ?nding of a sub-pixel moving vector in a H.263 moving
tion M(f) for ?nding the PSF(H) by using the regularization image restoration method can be described as below equation 3.
picture compressed method. In addition, when the up-sampling value is 3, it can be used in using of a 1/3 unit moving vector in a H.26L moving picture
Herein, the ?rst term of the right side of Equation 3 illus trates the credibility of the bi-linear interpolated image, the
35
compressed method. Herein, the H.263 and H.26L are moving picture com
pressed standards presented in the ITU-T (International Tele communications Union-Telecommunication).
second term of the right side illustrates increase of the stabil
ity of the system by providing the mitigation to the restored
image.
As described above, the present invention can be used for
In addition, the
means a norm, the ot is a regularization 40 improving the image quality at the post processor of the
parameter for determining the credibility and mitigation of
compressed digital image by using the interpolation method
the original image. In addition, the C is the two-dimensional
for getting the interpolated high resolution image from the low resolution image when the resolution of the digital image
high frequency ?lter for determining the mitigation of the
lowers due to the low resolution image sensor.
original image, in the present invention a two-dimensional Gaussian ?lter is used as the C.
45
In addition, the interpolation method of the present inven
tion can improve the image quality by ?nding the moving vector of the moving picture compressed type.
When a gradient operator is adapted to Equation 3 in order to get the high resolution image, it can be described as below
equation 4. What is claimed is: 50
Meanwhile, conventionally a repetition method is used in order to get the high resolution image and regularization parameter, but it is not suited to the moving picture processing because the method causes lots of computational complexity.
mg:
restoring a requested high resolution image f by ?nding an 55
Accordingly, in the present invention, the regularization parameter 0t is ?xed as ‘ l ’, and the high resolution image f can be found as below equation 5. 60
HT g (HTH + cTc) :
Pg
[1. A ?ltering control method for improving the image quality of a bi-linear interpolated image when recovering a high resolution image from a low resolution image, compris
Herein, the T means a transpose of a matrix.
[Equation 5]
added ?lter coe?icient Q of a PSF(P) and a bi-linear
interpolation ?lter B from an equation fIPgIPBZIQZ, wherein f is the high resolution image as requested, P is the PSF (Point Spread Function), g is the high resolution image found by the bi-linear interpolation method, and z is the low resolution image; wherein the high resolution image f can be restored by performing an added function M(f) de?nition process for ?nding the PSF(H) from an equation g:Bz:Hf+n, wherein B, H are bilinear interpolation ?lters, and n is a
When the PSF(P) is found by Equation 5, PSF(P):H/ (HTH+CTC) requires the lots of computational complexity for calculating an inverse matrix, however the PSF(P) in Equa
65
noise component generated by the assumed H; and wherein the added function M(f) is de?ned as M(f):||g— Hf]|2+0t||Cf]|2, wherein 0t is a regularization parameter,
US RE42,747 E 8
7 and C is a tWo-dimensional high frequency ?lter for
de?ning an added function M(f) for ?nding a PSF(H) from an equation g:BZ:Hf+n (Wherein B, H are bi-linear
?nding mitigation of the original image] [2. The ?ltering control method for improving the image quality of the bi-linear interpolated image according to claim
?lters, n is a noise component generated by an assumed H When the H is a PSF (Point Spread Function), f is a requested high resolution image, Z is a loW resolution
1, Wherein the regularization parameter 01 is ?xed as ‘l’ in order to reduce a computational complexity.]
image, and g is a high resolution image gotten by the
[3. The ?ltering control method for improving image qual ity of the b-linear interpolated image according to claim 1,
bi-linear interpolation method);
Wherein a tWo-dimensional gaussian ?lter is used as the tWo
?nding a PSF(P) of a fIPg function after ?nding the PSF (H) from the de?ned added function M(f); and
dimensional high frequency ?ler C in order to determine the
restoring the requested high resolution image f by ?nding
mitigation of the original image.]
an added ?lter coe?icient Q of the PSF(P) and interpo lation ?lter B from the equation fIPgIPBZIQZ; Wherein the added function M(f) is de?ned as M(f):||g— Hf]|2+01||Cf]|2, Wherein 01 is a regulariZation parameter, and C is a tWo-dimensional high frequency ?lter for
[4. A ?ltering control method for improving the image quality of a bi-linear interpolated image When recovering a high resolution image from a loW resolution image, compris 1ng:
restoring a requested high resolution image f by ?nding an
?nding the mitigation of the original image.] [8. The ?ltering control method for improving the image
added ?lter coe?icient Q of a PSF(P) and a bi-linear
interpolation ?lter B from an equation fIPgIPBZIQZ, Wherein f is the high resolution image as requested, P is the PSF (Point Spread Function), g is the high resolution image found by the bi-linear interpolation method, and Z is the loW resolution image; Wherein the high resolution image f can be restored by performing an added function M(f) de?nition process for ?nding the PSF(H) from an equation g:BZ:Hf+n,
quality a of the bi-linear interpolated image according to 20
in order to reduce a computational complexity.]
[9. The ?ltering control method for improving image qual ity of the bi-linear interpolated image according to claim 7, Wherein a tWo-dimensional gaussian ?lter is used as the tWo 25
noise component generated by the assumed H;
[10. A ?ltering control method for improving the image quality of a bilinear interpolated image When recovering a high resolution image from a loW resolution image, compris 30
G(k, 1) H(k, 1) = m,
dimensional high frequency ?lter C in order to determine the
mitigation of the original image.]
Wherein B, H are bi-linear interpolation ?lters, and n is a
Wherein the high resolution image f is restored by ?nding a PSF(P) of a fIPg function after ?nding the PSF(H) from the added function M(f); and Wherein the PSF(H) is found by using an equation
claim 7, Wherein the regulariZation parameter 01 is ?xed as ‘ l ’
35
1ng:
de?ning an added function for ?nding a PSF(H) from an equation g:BZ:Hf+n (Wherein B, H are bi-linear ?lters, n is a noise component generated by an assumed H When the H is a PST (Point Spread Function), f is a requested high resolution image, Z is a loW resolution
image, and g is a high resolution image gotten by the
G(k,l) is the component in the k,l frequency region of the bi-linear interpolated image, and F(k,l) is the component in the k,l frequency region of the high resolution image.] [5. A ?ltering control method for improving the image
bi-linear interpolation method); ?nding a PSF(P) of a fIPg function after ?nding the PSF (H) from the de?ned added function M(f); and
restoring the requested high resolution image f by ?nding
quality of a bi-linear interpolated image When recovering a high resolution image from a loW resolution image, compris
an added ?lter coe?icient Q of the PSF(P) and interpo lation ?lter B from the equation fIPgIPBZIQZ; Wherein the PSF(H) is found by an equation
1ng:
restoring a requested high resolution image f by ?nding an added ?lter coe?icient Q of a PSF(P) and a bi-linear
interpolation ?lter B from an equation fIPgIPBZIQZ, Wherein f is the high resolution image as requested, P is the PSF (Point Spread Function), g is the high resolution image found by the bi-linear interpolation method, and Z is the loW resolution image; Wherein the PSF(P) can be found by getting an IFT (Inverse Fourier Transform) by an equation
G(k, 1) H(k, 1) = m, 50
Wherein G(k,l) is the component in the k,l frequency region of the bi-linear interpolated image, and F(k,l) is the component in the k,l frequency region of the high
resolution image.] [11. A ?ltering control method for improving the image quality of a bi-linear interpolated image When recovering a high resolution image from a loW resolution image, compris 1ng:
[6. The ?ltering control method for improving the image quality of the bi-linear interpolated image according to claim
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?lters, n is a noise component generated by an assumed H When the H is a PSF (Point Spread Function), f is a requested high resolution image, Z is a loW resolution
5, Wherein the number of a kernal of the PSF(P) is set in accordance With an up-sampling value of the image.]
[7. A ?ltering control method for improving the image quality of a bilinear interpolated image When recovering a high resolution image from a loW resolution image, compris mg:
de?ning an added function M(f) for ?nding a PSF(H) from an equation g:BZ:Hf+n (Wherein B, H are bi-linear
image, and g is a high resolution image gotten by the 65
bi-linear interpolation method); ?nding a PSF(P) of a fIPg function after ?nding the PSF (H) from the de?ned added function M(f); and
US RE42,747 E 9
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restoring the requested high resolution image f by ?nding
16. The method ofclaim 13, wherein: the first filter coe?icient includes at least three di?'erent
an added ?lter coe?icient Q of the PSF(P) and interpo lation ?lter B from the equation fIPgIPBZIQZ; Wherein the PSF(P) is found by using an IFT (Inverse
coe?icient values, and generating the interpolated pixel data comprises dividing second interpolated pixel data by a sum of the at least
Fourier Transform) by an equation
three di/ferent coe?icient values. 1 7. The method ofclaim 13, wherein the?rst?lter coe?i cient and the second filter coe?icient comprise at least one
integer value. 18. The method ofclaim 13, wherein the?rst?lter coe?i cient and the secondfilter coe?icient are one.
19. The method of claim 13, wherein the second filter coe?icient is one.
[12. The ?ltering control method for improving the image quality of the bi-linear interpolated image according to claim 11, Wherein the number of a kernal of the PSF(P) is differently set in accordance With an up-sampling Value of the image.]
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13. A method for generating pixel data, the method per formed by at least one processor and the method comprising: generating a set of interpolated pixel data from a set of
original pixel data from an original image, wherein interpolated pixel data for a particular pixel is gener
ated by performing operations comprising:
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20. The method of claim 13, wherein the bit operation comprises a bit shift operation. 2]. The method ofclaim 13, wherein the original image is obtainedfrom a low-resolution imaging system. 22. The method ofclaim 13, wherein the original image is obtainedfrom video data configured to represent motion. 23. A digital video system comprising: a low-resolution imaging system configured to capture an
original image; and a processor configured to generate an interpolated image
selecting original pixel data,
from the original image and to obtain interpolatedpixel
obtaining at leastfirst and secondfilter coe?icients, the first and secondfilter coe?icients configured to inter
data for the interpolated image from original pixel data from the original image, wherein the interpolatedpixel datafor a particularpixel ofthe interpolated image is
polate the original pixel data, and the firstfilter coefl ?cient comprising weightingfactors having at least three at least three individual values;
applying thefirstfilter coe?icient to the selected original pixel data to produce ?rst interpolated original pixel data, wherein applying thefirstfilter coe?icient to the selected original pixel data comprises: multiplying each of the weighting factors and the selected original pixel data to produce weighted
pixel data; summing the weighted pixel data to produce the first interpolatedpixel data; and applying the second?lter coe?icient to the?rst interpo lated original pixel data to produce second interpo lated pixel data; and generating thepixel data byperforming a bit operation on
the second interpolated pixel data. 14. The method of claim 13, wherein the second filter coe?icient is a matrix including one or more individual
numeric values.
15. The method ofclaim 14, wherein the?rst?lter coe?i cient is a point spread function (P) and the second filter coe?icient is a bi-linear interpolation?lter
generated by performing operations comprising: selecting original pixel data for the interpolated image, obtaining at least first and secondfilter coe?icients, the first and secondfilter coe?icients configured to inter
polate the original pixel data, and the firstfilter coefl ?cient comprising weightingfactors having at least three at least three individual values,
applying thefirstfilter coe?icient to the selected original pixel data to produce ?rst interpolated original pixel data, wherein applying thefirstfilter coe?icient to the selected original pixel data comprises: multiplying each of the weighting factors and the selected original pixel data to produce weighted
pixel data; summing the weighted pixel data to produce the first
interpolated pixel data; applying the secondfilter coe?icient to the first interpo lated original pixel data to produce second interpo lated pixel data, and generating the interpolated image by performing a bit operation to the second interpolated pixel data. *
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